摘要:
A peak frequency detection device provided with: an n multiplication unit that multiplies each element of a digital data string by n (n is an integer of 2 or more); an FFT unit that derives, as a virtual peak frequency, a frequency that corresponds to the maximum value of a power spectrum that is obtained by performing a fast Fourier transform of a digital data string of N (N is an integer of a power of 2 and is determined in accordance with a sampling frequency (fs), a sampling resolution (ftg), and a time window length (Ttg)) sample frequencies (fs) that are multiplied by n; and a 1/n multiplication unit that outputs the value of the virtual peak frequency multiplied by 1/n as the peak frequency of the digital data string. The peak frequency detection device satisfies n≧1/(ftg×Ttg), fs/(n×ftg)≦N≦fs×Ttg, and fs>2×n×fch.
摘要:
A method and apparatus are provided for estimating the water speed of a first acoustic node D belonging to a network of acoustic nodes, at least some of the acoustic nodes being arranged along towed acoustic linear antennas (S). The method includes steps of: a) defining a N-dimensional base, the center of which is the first acoustic node and comprising a single axis, when N=1, or N non-collinear axes, when N=2 or N=3, each axis being associated with a base vector extending from the first acoustic node to another acoustic node; and b) estimating an amplitude of the water speed, as a function of: for each given other acoustic node defining the base vector: an acoustic propagation duration of an acoustic signal transmitted from the first acoustic node to the given other acoustic node, and an acoustic propagation duration of an acoustic signal transmitted from the given other acoustic nodes to the first acoustic node; and a value c of the underwater acoustic sound velocity.
摘要:
An ultrasonic sensor device includes a substrate, a piezoelectric vibrator, and a Q-factor adjuster. The piezoelectric vibrator includes a pair of detection electrodes that face each other in a thickness direction of the substrate and a piezoelectric body interposed between the electrodes. The piezoelectric vibrator provides a membrane structure which is formed on a surface of the substrate and has rigidity lower than that of a remaining portion of the substrate. An ultrasonic wave is transmitted by the piezoelectric vibrator, and its reflected wave is received by the same piezoelectric vibrator. The Q-factor adjuster adjusts a Q-factor of the piezoelectric vibrator so that the Q-factor can be larger during a transmission period where the piezoelectric vibrator transmits the ultrasonic wave than during a reception period where the piezoelectric vibrator receives the ultrasonic wave.
摘要:
An operation unit calculates a position of an obstacle with respect to a vehicle using a first distance and a second distance. The first distance is a distance to the obstacle measured by a first ultrasonic sensor (ultrasonic sensor) having a first microphone (microphone) at a first timing. The second distance is a distance to the obstacle measured by a second ultrasonic sensor (ultrasonic sensor) having a second microphone (microphone) at a second timing which is later than the first timing.
摘要:
The description relates to user control gestures. One example allows a speaker and a microphone to perform a first functionality. The example simultaneously utilizes the speaker and the microphone to perform a second functionality. The second functionality comprises capturing sound signals that originated from the speaker with the microphone and detecting Doppler shift in the sound signals. It correlates the Doppler shift with a user control gesture performed proximate to the computer and maps the user control gesture to a control function.
摘要:
An ultrasonic motion sensor device for lighting control, having a housing (10), preferably designed for ceiling-mounting, at least one ultrasonic transducer (11, 14) arranged in the housing (10) for sending and/or receiving ultrasonic waves through a housing opening associated with the ultrasonic transducer (11, 14), and having a control device (9) associated with the ultrasonic transducer (11, 14). The opening in the housing is formed by a horn which is spaced apart from the ultrasonic transducer (11, 14) via a resonator cavity arranged in the housing (2) and an impedance opening (21) is provided, preferably bounded by the horn, which the emitted and/or received ultrasonic waves (11, 14) are to pass through, the cross-sectional area (18) of which is less than a maximum cross-sectional area of the resonant cavity and than a maximum cross-sectional area of the horn.
摘要:
A hull inspection system useable for inspecting a hull of a maritime vessel passing a water volume at a first velocity, the system comprising: pulse emitting means, for being placed in the water volume and for emitting energy pulses into said water volume; sensing means, for being placed in the water volume, and being connected to the pulse emitting means, for sensing and measuring travelling time of energy pulses reflected by the passing vessel; a sensor data processing unit; connected to the sensing means, for processing data from the sensor means; a vessel data furnishing unit, connected to the sensor data processing unit, for providing vessel velocity data to the sensor data processing unit; wherein a three-dimensional representation of the hull of the maritime vessel is created based on data acquired by a procedure involving combination of data from a number of consecutive sensing means linear scans, and wherein the consecutive linear scans are acquired at consecutive moments in time, thereby enabling creation of a three dimensional representation of the hull.
摘要:
Exemplary embodiments of apparatus, method and computer accessible medium can be provided which can facilitate a determination of at least one characteristic of a structure. For example, it is possible to use at least one first arrangement which can be structured to provide at least one first transmitted radiation along a first axis and at least one second transmitted radiation along a second axis. The first and second transmitted radiations can impact the structure and generate respective first and second returned radiation. The first and second axis can be provided at a predetermined angle with respect with one another which is greater than 0. Further, at least one second arrangement can be provided which can be configured to receive data associated with the first and second returned radiations, and determine at least one relative velocity between the structure and the first arrangement along the first and second axes.
摘要:
A method (200) and system (220) for range detection is provided. The system can include a sensing unit (110) for detecting a location and movement of a first object (401), and a processor (107) for providing a measure of the movement. The processor can convert the measure to a coordinate signal for moving a second object (124) in accordance with a location and movement of the first object. The system can include a pulse shaper (109) for producing a pulse shaped signal (167) and a phase detector (101) for identifying a movement from a reflected signal (166). A portion of the pulse shaped signal can be a frequency modulated region (312), a constant frequency region (316), or a chirp region (324). In one arrangement, the pulse shaper can be a cascade of all-pass filters (515) for providing phase dispersion.
摘要:
The present invention relates to the angular calibration of passive reception systems such as sonars or active ones such as certain radars whose angular performance is inadequate. The invention proposes a method making it possible to perform antenna calibration using the detection system associated with this antenna under real operating conditions. The method according to the invention consists in making an immersed noisemaker deployed along a substantially rectilinear uniform trajectory and a submarine equipped with an antenna to be calibrated along any trajectory whatsoever, but nonrectilinear. The method according to the invention consists also in implementing a trajectography algorithm making it possible to determine the noisemaker-antenna relative distance at known instants ti, and to deduce therefrom the trajectory followed by the noisemaker as well as the bearing corresponding to the positions of the noisemaker at the measurement instants. The bearing thus calculated is compared with the bearing measurements carried out directly by the sonar associated with the antenna to be calibrated. This method applies in particular to the calibration of sonar antennas during their commissioning.